A Synthesis of Heteroaromatic Analogues of 1-Methyl-1,2,3,4-tetrahydroisoquinoline Using the Pummerer-Type Cyclization Reaction: Observation of Tandem Cyclization Reaction
作者:Yoshie Horiguchi、Keita Ogawa、Toshiaki Saitoh、Takehiro Sano
DOI:10.1248/cpb.52.214
日期:——
(2b). On the other hand, the sulfoxide (7c) carrying benzofuran as a nucleophile on reaction with TFAA yielded not only the Pummerer-type cyclization product (12a), but also the diastereoisomeric tandem cyclization products (13) and (14) having a noble 11-aza-2-oxa-7-thiatricyclo[4.3.3.0(1,5)]dodecane ring system (B). The formation of these products can be readily rationalized by the intervention of
当在室温下(三聚体反应)用三氟乙酸酐处理时,带有噻吩或苯并噻吩作为杂芳族亲核试剂的亚砜7b和7d以排他方式进行分子内烷基化反应,得到4,5,6,7-四氢-7-甲基-分别以高收率获得了4-苯基磺酰噻吩并[2,3-c]吡啶-6-甲醛(10)和相应的苯并噻吩衍生物(12b)。因此,该途径提供了生物学上有意义的氮杂环(1b)和(2b)。另一方面,在与TFAA反应时,带有苯并呋喃作为亲核试剂的亚砜(7c)不仅产生了Pummerer型环化产物(12a),而且还产生了具有贵金属11的非对映异构串联环化产物(13)和(14)。 -氮杂-2-氧杂-7-硫杂三环[4.3.3.0(1,5)]十二烷环系统(B)。